Coil stock holding and feeding device



March 3, 1953 J HALLER COIL STOCK HOLDING AND FEEDING DEVICE 3 Sheets-Sheet 1 Filed Dec. 31, 1947 3nnentor March 3, 1953 J. HALLER COIL STOCK HOLDING AND FEEDING DEVICE s Sheets-Sheet 2 Filed Dec. 31, 1947 I HTTYS JNVENTOR. fi;/J /Q//er flQ/LW YLWM 3 Sheets-Sheet 3 March 3, 1953 J HALLER con STOCK HOLDING AND FEEDING DEVICE Filed Dec. 51, 1947 Patented Mar. 3, 1953 COIL STOCK HOLDING AND FEEDING DEVICE I John Haller, Detroit, Mich.

Application December 31, 1947, Serial No. 795,079

Claims.

This invention relates to stock holding and feeding devices, and in particular, to reeling devices for automatically feedingcoil or strip stock to machines such as punching, stamping or cutting machines. One object of this invention is to provide a coil stock holding and feeding device which is operable automatically in timed relationship with a machine which it is serving, in such a manner that a predetermined amount of slack will be maintained in the coil stock being so fed. Another object is to provide a coil stock holding and feeding device wherein the strip stock is mounted on a reel which is rotated intermittently in accordance with the operation of control mechanism responsive to the amount of slack momentarily existing in the stock between the reel and the machine being served.

Another object is to provide a coil stock holding and feeding device of the above character wherein the motion of the machine being served actuates a hydraulic pump which in turn actuates a hydraulic motor operatively connected to the reel, under the control of a valve actuated in response to the amount of slack momentarily existing between the reel and the machine being served.

Another object is to provide a coil stock holdins and feeding device which will positively unreel the coilstock in accordance with the demand made upon the stock by the machine operating on the stock, thereby relieving the strain on the feeding mechanism associated with the machine being served and leaving it only the task of accurately feeding the stock step by step to the machine, thereby preventing the inaccurate feeding which would result from slippage of the stock due to the necessity of the feeding mechanism of the served machine having also to forcibly unreel the stock as well as feed it to the machine.

In the drawing:

Figure 1 is a diagrammatic side elevation of a coil stcck holding and feeding device connected to and operated by a punch press having stock feeding mechanism associated therewith;

Figure 2 is a top plan view of the right-hand end of Figure 1, showing the stock holding reel and its associatedmechanism;

Figure 3 is a vertical section along the line 3-3 in Figure 1 Figure 4 is an enlarged side elevation, partly in vertical section, of the hydraulic motor and control valve for the stock holding reel shown in Fisure.2;.. o

Figure 5 is an enlarged horizontal section along the line 55 in Figure 4;

Figure 6 is an enlarged horizontal section along the line 66 in Figure 4;

Figure '7 is an enlarged vertical sectionalon the line 'l-l in Figure 3 showing the operating pump;

Figure 8 is a horizontal section along the line 88 in Figure '7, taken immediately abovethe pump piston head;

Figure 9 is a horizontal section along the line 8 in Figure 7 taken through the piston head; Figure 10 is a fragmentary diagrammatic side elevation of a portion of Figure 1, showing a modified pump construction;

Figure 11 is a fragmentary side elevation of a modified coil stock holding and feeding device;

Figure 12 is a top plan View of the device shown in Figure 11; and

Figure 13 is a fragmentary top plan view of a further modified coil stock holding and feeding device.

Referring to the drawings in detail, Figures 1 and 3 show a coil stock holding and feeding de'- vice,generally designated iii, adapted to automatically feed coil stock I! at a predetermined tension to an intermittent feeding mechanism, generallydesignated l2, which is operated by and in timed relationship with a stock working ma chine generally designated 13, such as a punching; stamping, or cutting machine. The machine I3 is conventional and is shown diagrammatically as including a bed M to which a die '15 is secured as by the bolts I6 and. which has cavities l1 and 8 therein for receiving the punches l9 and 20 mounted on the punch support 2| which in turn is secured to the lower end of a ram or platen 22. The ram or platen 22 is provided with guide portions 23 which recipro-f cats in vertical guides 24 mounted on the frame of the machine l3 (not shown).

Bolted as at 25 to the platen 22 is a laterally extending reciprocating arm 26, the outer end of which is slottedas at 27 to slidably engage a stud 28 which carries a washer 38 and bolt 3!. The

' pin or stud :28 is mounted in a slide block 32 and passes through a radial adjustment slot 33 in a swinging arm 34. The slide block 32 issecured to the arm 34 by a bolt 35.

The arm 3-4 extends radially outward from'a hub 36 (Figure 1) and is held in position by a retaining washer 37 and bolt 38. The hub 35 is loosely mounted upon a rock shaft 39. Keyed or otherwise secured to therock shaft 39 (Figure .1.1 alm 4 br vin ared a y t in b at 3 from which arms 42 and 43 project axially and are provided with tangential threaded bores 44 and 45 to receive adjusting screws 46 and 41 locked in position by lock nuts 48 and 49.

The rock shaft 39 is journaled in suitable bearings (not shown) in the upper portion 50 of a housing 5|, forming a part of the intermittent feeding mechanism I2. The latter is disclosed and claimed in the Haller Patent No. 2,428,493. issued October 7, 1947, for Stock Feeding Mechanism for Punching, Stamping and Cutting Machines and its details form no part of the present invent-ion. By the mechanism 12, the coil stock II is fed automatically step by step to the punches I9 and die I5 as the platen 2-2 reciprocates.

Extending radially outward from the hub 40 in the opposite direction from the web M (Figure 3) is a pump-operating arm 52 having a ball head 53 on the end thereof engageable with a socket 54 in the upper end of a pump piston rod 55 which, on its lower end, carries a pump p'mton head generally designated 55'. The pump piston head 55 reciprocates in the bore 51 of a cylinder 58 forming a part of the housing 51, the foregoing piston and cylinder constituting a reel operating pump, generally designated 58 (Figure 7); The cylinder 58 is provided with a lateral extension 60 containing a reservoir IiI for the operating fluid, such as oil, the upper portion havinga threaded opening 62 receiving a closure cap '63. Similarly, the cylinder 58 is provided at its upper end with a threaded opening 64 into which is threaded a closure cap 65 having a bore 65 through the center thereof for the passage of the piston rod 55; The lower-end of the cylinder 58 also has a threaded opening 61 containing a screw cap 88 having an internal recess 69 in the center thereof permitting clearance for the lower end of the piston rod 55.

The piston rod 55 near its lower end is provided with an annular shoulder 10a (Figure '1) formed between it and a reduced diameter portion 10 which slidably engages the walls of a bore 1| (Figure 9) in the body 12 of the piston head 56.1 The bore 1| is also provided with longitudinal grooves 13'iforming a fluid passageway through which fluid can pass from opposite sides of the piston head 56. The lower end of the reduced diameter portion 10 of the piston rod 55 is provided with an annular groove 14 for receiving a split retaining ring 15.

The piston head body 12 on its upper side is provided with a countersunk recess 16 into which fits an annular disc 11 having a central bore 18 adapted to slidably receive the piston rod 55 adjacent its junction with its reduced diameter portion 10" (Figure '7). The annular disc 11 is provided circumferentially spaced threaded holes 19 which receive the threaded upper ends of headed studs. which are mounted in bores 8|. The-shanksof, the studs 80 pass through bores 82 inthe upper wall 83 of the cylinder body 12 and are encircled by spiral compression springs 83A.

The piston head body 12 is pierced by fluid passageways 84 (Figure 9), the upper ends of which are closed by the annular disc 11 which thereby serves as a yieldingly closed valve memher. The disc 11 is in turn provided with fluid passageways 85 spaced circumferentially from the passageways 84 (Figure 8) so that when the disc 1-1 is raised out of the countersunk recess 16 and thereby separated from engagement with the wall 83 (Figure'IVfluid-can pass upward'through 4 the passageways 85. By this construction the piston head 55 is provided with spring-pressed separable portions by which compressed fluid can pass through the piston head when it becomes trapped at the lower end of the cylinder bore 51 or when the pressure therein rises to an amount sufiicient to overcome the thrust of the coil spring 83A. On the upstroke, as shown in the chain line in Figure '1 and explained below in connection with'the operation fluid can pass downward from the reservoir GI and the upper end of the cylinder bore 51 through the grooves 13 into the lower end thereof. The lower end of the cylinder 58 is provided with a boss 86 which is provided with a threaded port 81 (Figure 3).

Threaded into the port 81 is the upper end of a conduit 88 which extends from the pump 59 to the strip stock holding and feeding device III, the lower end of the conduit 88 being threaded into the pump port 83 (Figure 4) in the casing 90 of a control valve 9 I Opposite the pump port 89 is a motor port 92 which is threaded to receive one end of a nipple 93; The ports ssand 92 open into a valve bore Q4 in which a valve plunger 95 is reciprocably mounted. The valve plunger 95 is provided with an annular cutaway portion 96 and an inner end 91 has a socket 98 which serves as an abutment for one end of a compression spring 99, the opposite end of which is seated against the inner end wall tilt) of the bore 94. The cutaway portion 88 is of such width as to leave a slight opening when the valve plunger 95 is in its closed position, so that fluid can pass downward from the motor port 92 to the pump port 89 when the pump 59 is in suction. The end wall I00 contains an air. vent I0 I. The valve plunger 95 is engaged by the rounded end I62 of a lever I03 which is pivotally mountedon the pin I04 between the yoke arms I05 extending outward from the valve casing 922. Mounted in the upper arm of the lever I03 is a control valve operating rod I06, the upper end of which is bent at right angles thereto and carries a roller I81 which rests on the upper surface of the stock strip II approximately at the point of maximum sag.

The upper end of the nipple 93 (Figure 4) is threaded into a port I08 in the cylinder I09 of a hydraulic motor HO having a cylinder bore II I in which reciprocates a piston I I2. The latter is connected to a piston rod I I3 which is surrounded by a compression spring I I4 which urges the piston head H2 and piston rod H3 downward. Threaded upon the upper end of the cylinder W5 is a support H5 which has a bore H6 in its horizontal portion H5a for the passage of the piston rod H3. The vertical portion II5b of the support H5 is provided with a vertical groove H1 which serves as a guideway for a vertically reciprocable slide H8. The slide H8 is bored as at H5 to receive the reduced diameter portion I20 of the piston rod H3, and is provided with a vertical guide groove I2I therein (Figure 5). The groove I2I is crossed by a pair of pins I 22' inserted in aligned holes I23, the pins passing through inclined slots I24 in a vertically slidable rack bar I25 having rack teeth I26 thereon. The rack bar I25 is thus slidable in an inclined direction into and out of the groove The slide H8 in its opposite side walls-is provided with elongated slots I21 (Figure 4) through which direct access is gained to the opposite sides of the rack bar I25. -In" order to provide a frictional drag upon the rack bar I25, two friction pins I23 (Figure 6) are reciprocably mounted in aligned bores 8Z9 (Figures 4 and 6) in the side walls of the support H5. The friction pins I28 are provided with sockets I39 which receive the ends of a U-shaped spring I3I. The latter is mounted in a U-shaped recess I32 in the support H5 and forces the friction pins I28 inward toward one another so that they form a retarding device with their inner ends yieldingly and fricti-onally engaging the sides of the rack bar IE5, causing the latter to act as a friction plunger.

The rack teeth I26 on the rack bar I in the lowered position of the latter mesh with corresponding teeth I33 on a gear or pinion te l which is pinned or otherwise secured to a shaft I which is journaled in a bore I35 in a bearing I3? mounted upon the upper end of an approxi mately triangular bearing bracket or coil holder supporting structure I38. Bolted to the bearing bracket 938 is an arm I35}, the outer end of which is bolted to the motor cylinder Ids (Figures 1 and 2). Mounted on the outer end of the shaft :35 is a reel or coil stock holder i ls consisting of a hub I li from which radial arms IE2 extend outward and are provided with L-shaped sup ports Hi3 bolted thereto. The coil stock II is wound upon the reel ltd and. is carried by the L-shaped supports I43.

In the operation of the invention, let it be assumed that the feeding mechanism I2 has been adjusted, as described in the previously-mentioned Haller Patent 2,428,493 of October '7, 1947, to feed the coil stock II to the left stepby-step in synchronisrn with the vertical reciprocation of the platen 22. This action is brought about by the up-and-down motion of the arm (Fig ure 1) swinging the arm 35 around the axis of the rock shaft 39. As the arm 36 swings to and fro vertically, it alternately engages the ends of the screws it and 4?, oscillating the web M (Figure 3) and with it the rock shaft 39 which operates the feeding mechanism i2 and advances the coil stock ii step-by-step.

At the same time, the arm 52, which is also carried by the hub t l, swings to and fro vertically, reciprocating the piston rod 55. As the piston rod moves downward, it forces liquid out of the lower end of the cylinder bore 5? (Figures 3 and 7) through the port 2? and conduit as into the pump port 89 of the control valve I EI (Figure 4). If the feeding operation of the feeding mechanism :2 has taken up a considerable amount of the slack in the coil stock ll between the feeding devices It and I2, the roller i J'I moves upward, swinging the rod Idii upward, permitting the coil spring 99 to push the reduced diameter portion 95 of the valve plunger 85 to the left, opening up the passageway between the pump and motor ports 89 and 92. The pressure fluid developed by the pump 59 thus passes into the lower end of the motor cylinder bore III, pushing the piston head IIE and piston rod H3 upward against the urge of the coil spring lid. The friction pins I28, however, exert a drag or retarding effect upon the rack bar I25 as the support IIS moves upward. The oo-action between the upwardly moving inclined slots I213 and the temporarily stationary pins I22 causes the rack bar 25 to be thrust horizontally to the left (Figure 1) meshing its teeth I26 with the teeth I33 on the gear or pinion I34. As soon as meshing takes place, the further upward motion of the slide IIE: overcomes the frictional drag of the pins I28 when the pins I22 reach the upper ends ofthe slots I2 1, causing the rack bar I25 to move upward, rotating the gear I33. This action ro tates the reel shaft I35 and with it the reel I40 in a counterclockwise direction, causing the coil stock II to slacken.

When the coil stock I I 'slackens, the roller It? and rod I66 move downward, thrusting the valve plunger M5 to the right to close off the major portion of the passageway between the ports t9 and 92. The liquid pressure thus rises in the cylinder 58 of the pump 59 and, when it exceeds the force of the coil springs 83A, causes the annular disc If to move upward relatively to the piston head body I2 uncovering the passage ways 8 (Figure 9). 'The fluid is thus enabled to pass through the passageways I34 and the space between the now separated piston head body l2 and annular disc 11, through the passageways (Figure 8) into the upper end of the cylinder bore 5? and thence into the reservoir BI. On the upstroke of the piston head 56, however, the piston rod 55 moves upward ahead of the piston head 58 until the split ring I5 engages the lower end of the piston head body I2, as shown in the chain lines at the bottom of Figure 7. The continued upward movement of the piston rod 55 causes fluid in the upper end of the cylinder bore 51 to move downward through the grooves '53 (Figures 7 and 9) into the lower end of the cylinder bore 57, since the upper ends of the grooves I3 have been uncovered by the upward motion of the piston rod 55.

' on the suction stroke of the piston head es, fluid will be withdrawn from the lower end of the motor cylinder bore II through the valve ti, whereupon the coil spring He will force the motor piston I I2 downward, carrying with it the slide H3. The friction pins I 28, however, still exert their frictional drag upon the sides of the rack bar 25, causing the action between the pins I22 and inclined slots I 24 to move the rack bar I25 horizontally to the right into the position shown in Figure 4, moving its teeth I26 out of mesh with the teeth I33 of the gear I34. Accordingly, on the downstroke of the motor piston I I2, the gear I35 is not rotated. Thus, the feeding device IE3 automatically regulates the unreeling 'of the stock from the reel I l!) and causes a constant slack to be'maintained between the feeding device It and the feeding mechanism I2 (Figure 1). As soon as this slack is taken up, the device It automatically unreels more of the coil stock II to maintain the slack.

In order to widen the range of operation of the reel-operating pump 59 and render it more adaptable to the varying requirement of different Widths and thicknesses of coil material, the cylinder 58 of the pump 53 is preferably provided with a longitudinal boss or enlargement I555 extending from the boss 86 to a boss I 45 and containing a by-pass passageway Itl (Figure 3). The passageway It? at its lower end opens into the port 81 and atv its upper end opens into a valve chamber Hi8 which is bored and threaded as at I49 to receive a valve member I59. The valve member I59 engages a seat at the mouth of a port I5! leading into the upper portion of the cylinder bore 5! above the point of highest ascent of the piston head 55.

The operation of the by-pass passageway I 4'! widens the range of operation of the pump 59 by permitting coil springs 83a (Figure '7) of the maximum desired pressure to be installed. The by-pass valve I59 can be adjusted to by-pass any desired portion of the fluid in the cylinder 58 during the down stroke of the piston 56, leaving the springs 8311 free to handle any pressure encountered above the pressure at which the springs 83a will hold the disc 11 closed against the ports 84 (Figures '7 and 8) Above this limiting pressure, the springs 83a will be compressed, lifting the plate 11 off the ports 84, as described previously, permitting excess fluid to escape through the ports 84 and 85 into the upper portion of the cylinder bore 51 and reservoir 6|. If the by-pass value I50 is screwed down tightly against its seat, closing the port II, then the disc 11 will lift only by a pressure exceeding the resisting pressure of the coil springs 83a.

The modification shown in Figure employs a pump I52 which is completely independent of the coil feeding mechanism I2 shown in Figure 1, so that an independent coil feeding mechanism I53 of any type may be used. The details of the coil-feeding mechanism. I53 are conventional and form no part of the present invention. The pump IE2 is operated by a bracket I54 secured as at I55 to the platen 22 and bored to receive the threaded piston rod I56 of the pump I52. Nuts I51 and I58 above and below the bracket I54 serve to regulate the stroke of the pump I52 for any given stroke of the platen 22.

The pump I52 is similar in construction to the pump 59 of Figure 7 except that its piston I59 is inverted as compared with the piston. 56, the piston rod I56 extending in the opposite direction from the piston rod 55. The outlet boss I60 of the pump I52 is therefore at the top instead of at the bottom of the cylinder and the port IGI receives the upper end of the pipe 88. The remainder of the arrangement is similar to that shown in Figure 1, and similar parts are similarly designated. The operation is also the same, with the exception that the pump I52 is of course operated directly by the bracket I54 from the platen 22 instead of indirectly through the mechanism for operating the feeding mechanism I2, as in Figure l.

The modified stock-holding and feeding device I62 of Figure 11 is similar in principle to that shown at It} in Figure l and similar parts are similarly designated. The reel I63 of the feeding device IE2 is intermittently rotated in a different manner from that shown in Figure 1. The upper end of the piston rod II3 of the fluid pressure motor cylinder III] in Figure 11, however, instead of being connected to. the rack and pinion mechanism shown in Figure l, is connected to a clevis I65 to which a link or connecting member I61 is pivoted as at I68 (Figure 11), the upper end of the link I61 being pivoted as at I69 to an approximately U-shaped operating arm I10. The latter has an extension I1I which engages the pivot pin I69 and the arm I12 carries a pair of pivot pins I13 and I14 which in turn carry spaced rollers or driving elements I and I16 which engage the opposite sides of the rim flange or annular projection I11 of a drum I18, the hub I19 of which is pinned or otherwise secured to the reel shaft I811.

The reel shaft I85 is journaled in a bore IS'i in the bearing portion E32 of a triangular bracket I83, the lower-portion of the latter being bolted or otherwise secured to the floor. Pinned or otherwise secured to the outer. end of the reel shaft I811! is the hub 584 of the reel i83. The latter is provided with L-shaped supports I85 which aresecured as at I86 to the reel arms I81 which radiate outward from the hub I84. The coil stock II is carried upon the supports I85. in

the. same mannerv as described above in connec.--

tion with Figure 1. The remaining arm I88 of the U-shaped operating arm I18 serves as a retaining member to prevent the rollers I15 from being disengaged from the flange I11 by moving in an axial direction.

The modification shown in Figure 13 is similar to that shown in Figures 11 and 12 except that the reel M32 is provided with an axially projecting flange I90 secured to the outer ends of the arms I81. The rollers I15 and I16 engage this flange 199 instead of the independent flange I11 on a drum I18 as in Figure 12.

The operation of the modifications shown in Figures 11 to 13 inclusive is generally similar to that described above in connection with Figure l, and hence requires no repetition except where it difliers. As the piston head H2 of the motor I I8 moves upward in Figure 11, it swings the arm I19 upward at its pivotal connection I69, causing the rollers I la and $16 to tightly grip the rim flange I11. The reciprocating motion of the piston rod H3 is thus converted into a rotary motion of the drum I18, accordingly rotating the reel I63. The modification of Figure 13 operates in a similar manner except that the rollers I15 and i 16 directly engage the reel periphery without the intervention of the drum 18. In either modification, the reel I63 is rotated stepby-step as long as the slack portion of the coil 21 remains sufficiently taut. When the slack II increases beyond the desired point, the roller I61 and its rod i538 drop downward, closing the valve 9! and temporarily halting the reciprocation of the motor I i=3 as explained in connection with Figure 1.

What I claim is:

l. A coil stock holding and feeding device for a sheet-material-working machine comprising a supporting structure, a coil stock holder rotatably mounted on said structure and adapted to hold a coil or" such stock with a slack portion thereof extending outwardly therefrom, a fluid pressure motor having a cylinder and a piston reciprocable therein, mechanism connected to said piston drivingly and selectively engaging said motor with and disengaging said motor from said holder to unreel stock therefrom, a fluid pressure pump, a hydraulic circuit connecting said pump to said motor, a power source drivingly connected to said pump, a control valve in said circuit interposed between said pump and said motor and having a shiftable valve member, a valve member operating structure engaging said stock between said holder and said machine, said control valve member operating structure being responsive to the attainment of a predetermined tautness in the slack portion of said stock for shifting said valve member to a position transmitting pressure fluid from said pump to said motor to unreel stock from said holder.

2. A coil stock holding and feeding device for a sheet-materialworking machine comprising a supporting structure, a coil stock holder rotatably mounted on said structure and adapted to hold a coil or" such stock with a slack portion thereof extending outwardly therefrom, a fluid pressure motor drivingly connected to said holder to unreel stock therefrom, a source of pressure fluid in circuit with said motor, and a control valve' interposed between said source and said motor and engaging said stock between said holder and said machine, said control valve being responsive to the attainment of a predetermined tautness in the slack portion of said stock for transmitting pressure fluid from said source to said motor, said motor comprising a fluid pressure cylinder and a piston reciprocable t erein, a gear wheel on said holder and gearing interposed between said motor and said gear wheel, and mechanism selectively engaging disenengaging said gearing with and from said gear wheel respectively whereby to drivingly and disengageably connect said piston to sai holder or disconnect said piston from said holder.

3. A coil stock holding and feeding device for a sheet-material-working machine comprising a supporting structure, a coil stool: holder rotate ably mounted on said structure and adapted to hold a coil of such stock with a slack portion thereof extending outwardly therefrom, a fluid pressure motor drivingly connected to said holdor to unreel stock therefrom, a source of pressure fluid in circuit with said motor, and a control valve interposed between said source and said motor and engaging said stock between said holder and said machine, said control valve be ing responsive to the attainrnent of a predetermined tautness in said stock for transmitting pressure fluid from said source to said motor, said motor comprising a fluid pressure cylinder and a piston reciprocable the sin, a rack connected to said piston, and a pinion on said holder, said rack being drivingly and selectively engageable with and disen ageable from said pinion.

e. A coil stock holding and feeding device for a sheetmaterial-woriring machine comprising a supporting structure, a coil stock holder rotatably mounted on said structure and adapted to hold a coil of such stock with a slack portion thereof extending outwardly therefrom, a fluid pressure motor mounted on said supporting structure and having a cylinder and a piston reciprocable therein, a rack movably connected to said piston, a pinion on said holder, a retarding device yieldably engaging said rack for effecting motion thereof into mesh with said pinion in response to the motion of said piston, a fluid pressure pump, a power source drivingly connected to said pump, and a control valve connected in circuit between said pump and said motor and having an operating member engaging said stock between said holder and said machine, said operating member being operable to transmit pressure fluid from said pump to said motor in response to the attainment of a predetermined tautness in the slack portion of said stock.

5. A coil stock holding and feeding device for a sheetunateriahworlsing machine comprising a supporting structure, a coil stock holder rotatably mounted on said structure and adapted to hold a coil of such stock with a portion thereof extending outwardly therefrom, a fluid p *essure motor mounted on said supporting structure and having a cylinder and a piston reciprocable therein, a rack movably connected to said piston and having a pin and inclined slot connection therewith, a pinion on said holder, a retarding device yieldably engaging said rack for effecting motion thereof into mesh with said pinion in response to the motion of said piston, a fluid pressure pump, a power source drivingly connected to said pump, and a control valve connected in circuit between said pump and said motor and havan operating member en aging said stool; between said holder and said machine, said oper ating member being operable to transmit pressure fluid from said pump to said motor in re sponse to the attainment of a predetermined tautness in the slack portion of said stock.

6. A coil stock holding and feeding device for a sheet-material-working machine comprising a supporting structure, a coil stock holder rotatably mounted on said structure and adapted to hold a coil of such stock with a slack portion thereof extending outwardly therefrom, a fluid pressure motor mounted on said supporting structure and having a cylinder and a piston reciprocable therein, a rack movably connected to said piston, a, pinion on said holder, a retarding device including a yieldingly urged friction plunger yieldably engaging said rack for effecting motion thereof into mesh with said pinion in response to the motion of said piston, a fluid pressure pump, a power source drivingly connected to said pump, and a control valve connected in circuit between said pump and said motor and having an operating member engaging said stock between said holder and said machine, said operating member being operable to transmit pressure fluid from said pump to said motor in response to the attainment of a predetermined tautness in the slack portion of said stock.

7. A coil stock holding and feeding device for a sheet-material-working machine comprising a supporting structure, a coil stock holder r0- tatably mounted on said structure and adapted to hold a coil of such stock with a slack portion thereof extending. outwardly therefrom, a fluid pressure motor mounted on said supporting structure and having a cylinder and a piston reciprocable therein, a rack movably connected to said piston, and having a pin and inclined slot connection therewith, a pinion on said holder, a retarding device including a yieldingly urged friction plunger yieldably engaging said rack for effecting motion thereof into mesh with said pinion in response to the motion of said piston, a fluid pressure pump, a power source drivingly connected to said pump, and a control valve connected in circuit between said pump and said motor and having an operating member engaging said stock between said holder and said machine, said operating member being operable to transmit pressure fluid from said pump to said motor in response to the attainment of a predetermined tautness in the slack portion of said stock.

8. A coil stock holding and feeding device for a sheet-material-working machine comprising a supporting structure, a coil stock holder rotatably mounted on said structure and adapted to hold a coil of such stock with a slack portion thereof extending outwardly therefrom, a fluid pressure motor drivingly connected to said holder to unreel stock therefrom, a fluid pressure pump in circuit with said motor, a mechanism drivingingly connecting said pump to a moving part of said machine, and a control valve interposed between said pump and said motor and having a valve operating structure engaging said stock between said holder and said machine, said control valve being responslve to the attainment of a predetermined tautness in the slack portion of said stock for transmitting pressure fluid from said pump to said motor, said pump having a cylinder and a piston reciprocable therein, said piston having a yieldingly closed valve therein for passing fluid therethrough in response to the attainment of a predetermined pressure in said cylinder.

9. A coil stock holding and feeding device for a sheet-material-working machine comprising a supporting structure, a coil stockholder rotatably mounted on said structure and adapted to hold a coil of such stock with a slack portion thereof extending outwardly therefrom; a" fluid pressure motor drivingly connected tosaid holder to unreel stock therefrom, a fluid pressure pump in circuit with said motor, a mechanism drivingly connecting said pump to a moving part of said machine, and a control valve interposed ably mounted in said bore and having a shoulder closing said passageway during reciprocation of said piston rod in one direction and opening said passageway during reciprocation thereof in the opposite direction.

10. A coil stock holding and feeding device or a sheet-material-working machine comprising a supporting structure, a coil stock holder rotatably mounted on said structure and adapted to hold a coil of such stock with a slack portion thereof extending outwardly therefrom, a fluid pressure motor mounted on said supporting structure and having a. cylinder and a piston reciprocable therein, a connecting member attach'ed tosaid piston;-said stock holder having an annular projection'thereon, a plurality of spaced driving elements engageable with the opposite sidesof said projection and connected to "said connecting member, said driving elements being responsive to the piston stroke in one direction todrivingly engage said projection to rotate said stock holder and responsive to the piston stroke in the opposite direction to slip relatively ,to said projection, a fluid pressure pump, a power source drivingly connected to said pump, anda control valve connected in circuit between said'pump and said motor and having an operating member engaging said stock between said holder and said machine, said operating member being operable to transmit pressure fluid from said pump to said motor in response to the attainment of a predetermined tautness in the slack portion of said stock.

JOHN ,HALLER.

.. REFERENCES CITED The iollowingr'eferences are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,055,785 Crowther V Sept. 29, 1936 2,066,488 Schmied Jan. 5, 1937 2,164,599 Tyler. July 4, 1939 2,203,354 Harrington vet a1. June 4, 1940 2,278,240 Calleson etal Mar. 31, 1942 

